U.S. Pat. No. 4,154,899 describes the use of pigment, clay and modified starch ether for coating compositions which are applied to paper during manufacture European Patent Application EP 307-795 describes a pigment dispersion used for paper coating which can contain modified starch, galactomannan, MC (methylcellulose) or CMC (carboxymethylcellulose). A quaternary starch ether is employed in the papermaking method of U.S. Pat. No. 4,840,705.
It is further known from Aqualon.RTM. publication 250-11C, Natrosol.RTM.--Hydroxyethylcellulose--A Nonionic Water Soluble Polymer--Physical and Chemical Properties, that this cellulosic can be used in coating colors and size press solutions to control water binding, solids holdout and rheology. Hercules Incorporated product data publication 456-2, Natrosol.RTM. R in Pigmented Coatings for Paper and Paperboard, contains viscosity data useful for selection of a grade of product for a papermaking application.
U.S. Pat. Nos. 4,834,207, 4,228,277 and 4,243,802 describe hydrophobically modified hydroxyethylcellulose (HMHEC) for use in latex paints and shampoos. Chain lengths from C10 to C24 provide the hydrophobic modification.
Still it remained for the present invention to teach a new and useful coating composition and process of use applicable to paper manufacture.